bgp: fix bug of not taking care of withdrawn label
bgp: fix bug of not taking care of withdrawn label

Reported-by: Toshiki Tsuboi <3612e803c7a6187f9767b9f153add7d8be62b078@gmail.com>
Signed-off-by: ISHIDA Wataru <15703620d0b11e835ab4f34ebf88f2f40cce783e@lab.ntt.co.jp>
Signed-off-by: FUJITA Tomonori <93dac1fe9c4b2a3957982200319981492ad4976e@lab.ntt.co.jp>

gareging/SDN_Framework,iwaseyusuke/ryu,shinpeimuraoka/ryu,habibiefaried/ryu,John-Lin/ryu,gareging/SDN_Framework,lagopus/ryu-lagopus-ext,osrg/ryu,OpenState-SDN/ryu,lagopus/ryu-lagopus-ext,iwaseyusuke/ryu,Zouyiran/ryu,OpenState-SDN/ryu,alanquillin/ryu,elahejalalpour/ELRyu,darjus-amzn/ryu,iwaseyusuke/ryu,lsqtongxin/ryu,iwaseyusuke/ryu,sivaramakrishnansr/ryu,habibiefaried/ryu,TakeshiTseng/ryu,zyq001/ryu,fujita/ryu,lsqtongxin/ryu,takahashiminoru/ryu,gareging/SDN_Framework,zyq001/ryu,fujita/ryu,Tejas-Subramanya/RYU_MEC,fujita/ryu,darjus-amzn/ryu,ttsubo/ryu,alanquillin/ryu,diogommartins/ryu,StephenKing/ryu,lsqtongxin/ryu,fkakuma/ryu,lagopus/ryu-lagopus-ext,StephenKing/ryu,Zouyiran/ryu,elahejalalpour/ELRyu,zyq001/ryu,gareging/SDN_Framework,OpenState-SDN/ryu,pichuang/ryu,lsqtongxin/ryu,sivaramakrishnansr/ryu,sivaramakrishnansr/ryu,elahejalalpour/ELRyu,hisaharu/ryu,lsqtongxin/ryu,fujita/ryu,Tejas-Subramanya/RYU_MEC,Tejas-Subramanya/RYU_MEC,takahashiminoru/ryu,hisaharu/ryu,alanquillin/ryu,lagopus/ryu-lagopus-ext,John-Lin/ryu,Zouyiran/ryu,ttsubo/ryu,alanquillin/ryu,shinpeimuraoka/ryu,ttsubo/ryu,Tejas-Subramanya/RYU_MEC,Zouyiran/ryu,pichuang/ryu,zangree/ryu,zangree/ryu,OpenState-SDN/ryu,iwaseyusuke/ryu,shinpeimuraoka/ryu,hisaharu/ryu,fkakuma/ryu,shinpeimuraoka/ryu,takahashiminoru/ryu,TakeshiTseng/ryu,John-Lin/ryu,TakeshiTseng/ryu,habibiefaried/ryu,elahejalalpour/ELRyu,pichuang/ryu,StephenKing/ryu,pichuang/ryu,osrg/ryu,StephenKing/ryu,fujita/ryu,gareging/SDN_Framework,osrg/ryu,shinpeimuraoka/ryu,TakeshiTseng/ryu,alanquillin/ryu,zyq001/ryu,ttsubo/ryu,John-Lin/ryu,fkakuma/ryu,elahejalalpour/ELRyu,habibiefaried/ryu,zangree/ryu,takahashiminoru/ryu,darjus-amzn/ryu,hisaharu/ryu,hisaharu/ryu,zangree/ryu,diogommartins/ryu,Tejas-Subramanya/RYU_MEC,TakeshiTseng/ryu,osrg/ryu,habibiefaried/ryu,darjus-amzn/ryu,Zouyiran/ryu,diogommartins/ryu,takahashiminoru/ryu,ttsubo/ryu,pichuang/ryu,fkakuma/ryu,John-Lin/ryu,fkakuma/ryu,zyq001/ryu,zangree/ryu,darjus-amzn/ryu,diogommartins/ryu,StephenKing/ryu,OpenState-SDN/ryu,lagopus/ryu-lagopus-ext,sivaramakrishnansr/ryu,sivaramakrishnansr/ryu,diogommartins/ryu,osrg/ryu